2 FreeRTOS V7.3.0 - Copyright (C) 2012 Real Time Engineers Ltd.
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4 FEATURES AND PORTS ARE ADDED TO FREERTOS ALL THE TIME. PLEASE VISIT
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5 http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.
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7 ***************************************************************************
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9 * FreeRTOS tutorial books are available in pdf and paperback. *
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10 * Complete, revised, and edited pdf reference manuals are also *
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13 * Purchasing FreeRTOS documentation will not only help you, by *
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14 * ensuring you get running as quickly as possible and with an *
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15 * in-depth knowledge of how to use FreeRTOS, it will also help *
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16 * the FreeRTOS project to continue with its mission of providing *
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17 * professional grade, cross platform, de facto standard solutions *
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18 * for microcontrollers - completely free of charge! *
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20 * >>> See http://www.FreeRTOS.org/Documentation for details. <<< *
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22 * Thank you for using FreeRTOS, and thank you for your support! *
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24 ***************************************************************************
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27 This file is part of the FreeRTOS distribution.
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29 FreeRTOS is free software; you can redistribute it and/or modify it under
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30 the terms of the GNU General Public License (version 2) as published by the
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31 Free Software Foundation AND MODIFIED BY the FreeRTOS exception.
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32 >>>NOTE<<< The modification to the GPL is included to allow you to
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33 distribute a combined work that includes FreeRTOS without being obliged to
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34 provide the source code for proprietary components outside of the FreeRTOS
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35 kernel. FreeRTOS is distributed in the hope that it will be useful, but
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36 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
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37 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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38 more details. You should have received a copy of the GNU General Public
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39 License and the FreeRTOS license exception along with FreeRTOS; if not it
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40 can be viewed here: http://www.freertos.org/a00114.html and also obtained
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41 by writing to Richard Barry, contact details for whom are available on the
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46 ***************************************************************************
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48 * Having a problem? Start by reading the FAQ "My application does *
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49 * not run, what could be wrong?" *
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51 * http://www.FreeRTOS.org/FAQHelp.html *
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53 ***************************************************************************
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56 http://www.FreeRTOS.org - Documentation, training, latest versions, license
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57 and contact details.
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59 http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
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60 including FreeRTOS+Trace - an indispensable productivity tool.
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62 Real Time Engineers ltd license FreeRTOS to High Integrity Systems, who sell
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63 the code with commercial support, indemnification, and middleware, under
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64 the OpenRTOS brand: http://www.OpenRTOS.com. High Integrity Systems also
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65 provide a safety engineered and independently SIL3 certified version under
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66 the SafeRTOS brand: http://www.SafeRTOS.com.
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73 #ifndef INC_FREERTOS_H
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74 #error "include FreeRTOS.h" must appear in source files before "include queue.h"
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82 #include "mpu_wrappers.h"
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85 * Type by which queues are referenced. For example, a call to xQueueCreate
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86 * returns (via a pointer parameter) an xQueueHandle variable that can then
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87 * be used as a parameter to xQueueSend(), xQueueReceive(), etc.
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89 typedef void * xQueueHandle;
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92 /* For internal use only. */
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93 #define queueSEND_TO_BACK ( 0 )
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94 #define queueSEND_TO_FRONT ( 1 )
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96 /* For internal use only. These definitions *must* match those in queue.c. */
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97 #define queueQUEUE_TYPE_BASE ( 0U )
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98 #define queueQUEUE_TYPE_MUTEX ( 1U )
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99 #define queueQUEUE_TYPE_COUNTING_SEMAPHORE ( 2U )
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100 #define queueQUEUE_TYPE_BINARY_SEMAPHORE ( 3U )
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101 #define queueQUEUE_TYPE_RECURSIVE_MUTEX ( 4U )
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106 xQueueHandle xQueueCreate(
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107 unsigned portBASE_TYPE uxQueueLength,
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108 unsigned portBASE_TYPE uxItemSize
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112 * Creates a new queue instance. This allocates the storage required by the
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113 * new queue and returns a handle for the queue.
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115 * @param uxQueueLength The maximum number of items that the queue can contain.
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117 * @param uxItemSize The number of bytes each item in the queue will require.
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118 * Items are queued by copy, not by reference, so this is the number of bytes
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119 * that will be copied for each posted item. Each item on the queue must be
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122 * @return If the queue is successfully create then a handle to the newly
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123 * created queue is returned. If the queue cannot be created then 0 is
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134 void vATask( void *pvParameters )
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136 xQueueHandle xQueue1, xQueue2;
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138 // Create a queue capable of containing 10 unsigned long values.
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139 xQueue1 = xQueueCreate( 10, sizeof( unsigned long ) );
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142 // Queue was not created and must not be used.
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145 // Create a queue capable of containing 10 pointers to AMessage structures.
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146 // These should be passed by pointer as they contain a lot of data.
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147 xQueue2 = xQueueCreate( 10, sizeof( struct AMessage * ) );
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150 // Queue was not created and must not be used.
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153 // ... Rest of task code.
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156 * \defgroup xQueueCreate xQueueCreate
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157 * \ingroup QueueManagement
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159 #define xQueueCreate( uxQueueLength, uxItemSize ) xQueueGenericCreate( uxQueueLength, uxItemSize, queueQUEUE_TYPE_BASE )
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164 portBASE_TYPE xQueueSendToToFront(
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165 xQueueHandle xQueue,
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166 const void * pvItemToQueue,
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167 portTickType xTicksToWait
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171 * This is a macro that calls xQueueGenericSend().
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173 * Post an item to the front of a queue. The item is queued by copy, not by
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174 * reference. This function must not be called from an interrupt service
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175 * routine. See xQueueSendFromISR () for an alternative which may be used
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178 * @param xQueue The handle to the queue on which the item is to be posted.
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180 * @param pvItemToQueue A pointer to the item that is to be placed on the
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181 * queue. The size of the items the queue will hold was defined when the
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182 * queue was created, so this many bytes will be copied from pvItemToQueue
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183 * into the queue storage area.
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185 * @param xTicksToWait The maximum amount of time the task should block
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186 * waiting for space to become available on the queue, should it already
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187 * be full. The call will return immediately if this is set to 0 and the
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188 * queue is full. The time is defined in tick periods so the constant
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189 * portTICK_RATE_MS should be used to convert to real time if this is required.
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191 * @return pdTRUE if the item was successfully posted, otherwise errQUEUE_FULL.
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201 unsigned long ulVar = 10UL;
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203 void vATask( void *pvParameters )
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205 xQueueHandle xQueue1, xQueue2;
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206 struct AMessage *pxMessage;
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208 // Create a queue capable of containing 10 unsigned long values.
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209 xQueue1 = xQueueCreate( 10, sizeof( unsigned long ) );
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211 // Create a queue capable of containing 10 pointers to AMessage structures.
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212 // These should be passed by pointer as they contain a lot of data.
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213 xQueue2 = xQueueCreate( 10, sizeof( struct AMessage * ) );
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219 // Send an unsigned long. Wait for 10 ticks for space to become
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220 // available if necessary.
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221 if( xQueueSendToFront( xQueue1, ( void * ) &ulVar, ( portTickType ) 10 ) != pdPASS )
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223 // Failed to post the message, even after 10 ticks.
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229 // Send a pointer to a struct AMessage object. Don't block if the
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230 // queue is already full.
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231 pxMessage = & xMessage;
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232 xQueueSendToFront( xQueue2, ( void * ) &pxMessage, ( portTickType ) 0 );
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235 // ... Rest of task code.
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238 * \defgroup xQueueSend xQueueSend
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239 * \ingroup QueueManagement
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241 #define xQueueSendToFront( xQueue, pvItemToQueue, xTicksToWait ) xQueueGenericSend( ( xQueue ), ( pvItemToQueue ), ( xTicksToWait ), queueSEND_TO_FRONT )
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246 portBASE_TYPE xQueueSendToBack(
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247 xQueueHandle xQueue,
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248 const void * pvItemToQueue,
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249 portTickType xTicksToWait
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253 * This is a macro that calls xQueueGenericSend().
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255 * Post an item to the back of a queue. The item is queued by copy, not by
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256 * reference. This function must not be called from an interrupt service
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257 * routine. See xQueueSendFromISR () for an alternative which may be used
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260 * @param xQueue The handle to the queue on which the item is to be posted.
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262 * @param pvItemToQueue A pointer to the item that is to be placed on the
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263 * queue. The size of the items the queue will hold was defined when the
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264 * queue was created, so this many bytes will be copied from pvItemToQueue
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265 * into the queue storage area.
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267 * @param xTicksToWait The maximum amount of time the task should block
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268 * waiting for space to become available on the queue, should it already
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269 * be full. The call will return immediately if this is set to 0 and the queue
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270 * is full. The time is defined in tick periods so the constant
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271 * portTICK_RATE_MS should be used to convert to real time if this is required.
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273 * @return pdTRUE if the item was successfully posted, otherwise errQUEUE_FULL.
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283 unsigned long ulVar = 10UL;
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285 void vATask( void *pvParameters )
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287 xQueueHandle xQueue1, xQueue2;
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288 struct AMessage *pxMessage;
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290 // Create a queue capable of containing 10 unsigned long values.
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291 xQueue1 = xQueueCreate( 10, sizeof( unsigned long ) );
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293 // Create a queue capable of containing 10 pointers to AMessage structures.
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294 // These should be passed by pointer as they contain a lot of data.
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295 xQueue2 = xQueueCreate( 10, sizeof( struct AMessage * ) );
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301 // Send an unsigned long. Wait for 10 ticks for space to become
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302 // available if necessary.
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303 if( xQueueSendToBack( xQueue1, ( void * ) &ulVar, ( portTickType ) 10 ) != pdPASS )
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305 // Failed to post the message, even after 10 ticks.
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311 // Send a pointer to a struct AMessage object. Don't block if the
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312 // queue is already full.
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313 pxMessage = & xMessage;
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314 xQueueSendToBack( xQueue2, ( void * ) &pxMessage, ( portTickType ) 0 );
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317 // ... Rest of task code.
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320 * \defgroup xQueueSend xQueueSend
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321 * \ingroup QueueManagement
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323 #define xQueueSendToBack( xQueue, pvItemToQueue, xTicksToWait ) xQueueGenericSend( ( xQueue ), ( pvItemToQueue ), ( xTicksToWait ), queueSEND_TO_BACK )
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328 portBASE_TYPE xQueueSend(
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329 xQueueHandle xQueue,
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330 const void * pvItemToQueue,
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331 portTickType xTicksToWait
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335 * This is a macro that calls xQueueGenericSend(). It is included for
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336 * backward compatibility with versions of FreeRTOS.org that did not
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337 * include the xQueueSendToFront() and xQueueSendToBack() macros. It is
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338 * equivalent to xQueueSendToBack().
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340 * Post an item on a queue. The item is queued by copy, not by reference.
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341 * This function must not be called from an interrupt service routine.
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342 * See xQueueSendFromISR () for an alternative which may be used in an ISR.
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344 * @param xQueue The handle to the queue on which the item is to be posted.
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346 * @param pvItemToQueue A pointer to the item that is to be placed on the
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347 * queue. The size of the items the queue will hold was defined when the
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348 * queue was created, so this many bytes will be copied from pvItemToQueue
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349 * into the queue storage area.
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351 * @param xTicksToWait The maximum amount of time the task should block
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352 * waiting for space to become available on the queue, should it already
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353 * be full. The call will return immediately if this is set to 0 and the
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354 * queue is full. The time is defined in tick periods so the constant
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355 * portTICK_RATE_MS should be used to convert to real time if this is required.
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357 * @return pdTRUE if the item was successfully posted, otherwise errQUEUE_FULL.
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367 unsigned long ulVar = 10UL;
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369 void vATask( void *pvParameters )
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371 xQueueHandle xQueue1, xQueue2;
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372 struct AMessage *pxMessage;
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374 // Create a queue capable of containing 10 unsigned long values.
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375 xQueue1 = xQueueCreate( 10, sizeof( unsigned long ) );
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377 // Create a queue capable of containing 10 pointers to AMessage structures.
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378 // These should be passed by pointer as they contain a lot of data.
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379 xQueue2 = xQueueCreate( 10, sizeof( struct AMessage * ) );
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385 // Send an unsigned long. Wait for 10 ticks for space to become
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386 // available if necessary.
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387 if( xQueueSend( xQueue1, ( void * ) &ulVar, ( portTickType ) 10 ) != pdPASS )
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389 // Failed to post the message, even after 10 ticks.
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395 // Send a pointer to a struct AMessage object. Don't block if the
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396 // queue is already full.
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397 pxMessage = & xMessage;
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398 xQueueSend( xQueue2, ( void * ) &pxMessage, ( portTickType ) 0 );
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401 // ... Rest of task code.
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404 * \defgroup xQueueSend xQueueSend
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405 * \ingroup QueueManagement
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407 #define xQueueSend( xQueue, pvItemToQueue, xTicksToWait ) xQueueGenericSend( ( xQueue ), ( pvItemToQueue ), ( xTicksToWait ), queueSEND_TO_BACK )
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413 portBASE_TYPE xQueueGenericSend(
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414 xQueueHandle xQueue,
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415 const void * pvItemToQueue,
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416 portTickType xTicksToWait
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417 portBASE_TYPE xCopyPosition
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421 * It is preferred that the macros xQueueSend(), xQueueSendToFront() and
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422 * xQueueSendToBack() are used in place of calling this function directly.
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424 * Post an item on a queue. The item is queued by copy, not by reference.
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425 * This function must not be called from an interrupt service routine.
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426 * See xQueueSendFromISR () for an alternative which may be used in an ISR.
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428 * @param xQueue The handle to the queue on which the item is to be posted.
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430 * @param pvItemToQueue A pointer to the item that is to be placed on the
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431 * queue. The size of the items the queue will hold was defined when the
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432 * queue was created, so this many bytes will be copied from pvItemToQueue
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433 * into the queue storage area.
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435 * @param xTicksToWait The maximum amount of time the task should block
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436 * waiting for space to become available on the queue, should it already
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437 * be full. The call will return immediately if this is set to 0 and the
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438 * queue is full. The time is defined in tick periods so the constant
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439 * portTICK_RATE_MS should be used to convert to real time if this is required.
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441 * @param xCopyPosition Can take the value queueSEND_TO_BACK to place the
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442 * item at the back of the queue, or queueSEND_TO_FRONT to place the item
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443 * at the front of the queue (for high priority messages).
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445 * @return pdTRUE if the item was successfully posted, otherwise errQUEUE_FULL.
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455 unsigned long ulVar = 10UL;
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457 void vATask( void *pvParameters )
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459 xQueueHandle xQueue1, xQueue2;
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460 struct AMessage *pxMessage;
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462 // Create a queue capable of containing 10 unsigned long values.
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463 xQueue1 = xQueueCreate( 10, sizeof( unsigned long ) );
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465 // Create a queue capable of containing 10 pointers to AMessage structures.
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466 // These should be passed by pointer as they contain a lot of data.
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467 xQueue2 = xQueueCreate( 10, sizeof( struct AMessage * ) );
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473 // Send an unsigned long. Wait for 10 ticks for space to become
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474 // available if necessary.
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475 if( xQueueGenericSend( xQueue1, ( void * ) &ulVar, ( portTickType ) 10, queueSEND_TO_BACK ) != pdPASS )
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477 // Failed to post the message, even after 10 ticks.
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483 // Send a pointer to a struct AMessage object. Don't block if the
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484 // queue is already full.
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485 pxMessage = & xMessage;
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486 xQueueGenericSend( xQueue2, ( void * ) &pxMessage, ( portTickType ) 0, queueSEND_TO_BACK );
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489 // ... Rest of task code.
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492 * \defgroup xQueueSend xQueueSend
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493 * \ingroup QueueManagement
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495 signed portBASE_TYPE xQueueGenericSend( xQueueHandle pxQueue, const void * const pvItemToQueue, portTickType xTicksToWait, portBASE_TYPE xCopyPosition );
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500 portBASE_TYPE xQueuePeek(
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501 xQueueHandle xQueue,
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503 portTickType xTicksToWait
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506 * This is a macro that calls the xQueueGenericReceive() function.
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508 * Receive an item from a queue without removing the item from the queue.
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509 * The item is received by copy so a buffer of adequate size must be
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510 * provided. The number of bytes copied into the buffer was defined when
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511 * the queue was created.
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513 * Successfully received items remain on the queue so will be returned again
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514 * by the next call, or a call to xQueueReceive().
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516 * This macro must not be used in an interrupt service routine.
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518 * @param pxQueue The handle to the queue from which the item is to be
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521 * @param pvBuffer Pointer to the buffer into which the received item will
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524 * @param xTicksToWait The maximum amount of time the task should block
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525 * waiting for an item to receive should the queue be empty at the time
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526 * of the call. The time is defined in tick periods so the constant
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527 * portTICK_RATE_MS should be used to convert to real time if this is required.
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528 * xQueuePeek() will return immediately if xTicksToWait is 0 and the queue
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531 * @return pdTRUE if an item was successfully received from the queue,
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532 * otherwise pdFALSE.
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542 xQueueHandle xQueue;
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544 // Task to create a queue and post a value.
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545 void vATask( void *pvParameters )
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547 struct AMessage *pxMessage;
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549 // Create a queue capable of containing 10 pointers to AMessage structures.
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550 // These should be passed by pointer as they contain a lot of data.
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551 xQueue = xQueueCreate( 10, sizeof( struct AMessage * ) );
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554 // Failed to create the queue.
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559 // Send a pointer to a struct AMessage object. Don't block if the
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560 // queue is already full.
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561 pxMessage = & xMessage;
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562 xQueueSend( xQueue, ( void * ) &pxMessage, ( portTickType ) 0 );
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564 // ... Rest of task code.
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567 // Task to peek the data from the queue.
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568 void vADifferentTask( void *pvParameters )
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570 struct AMessage *pxRxedMessage;
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574 // Peek a message on the created queue. Block for 10 ticks if a
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575 // message is not immediately available.
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576 if( xQueuePeek( xQueue, &( pxRxedMessage ), ( portTickType ) 10 ) )
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578 // pcRxedMessage now points to the struct AMessage variable posted
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579 // by vATask, but the item still remains on the queue.
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583 // ... Rest of task code.
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586 * \defgroup xQueueReceive xQueueReceive
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587 * \ingroup QueueManagement
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589 #define xQueuePeek( xQueue, pvBuffer, xTicksToWait ) xQueueGenericReceive( ( xQueue ), ( pvBuffer ), ( xTicksToWait ), pdTRUE )
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594 portBASE_TYPE xQueueReceive(
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595 xQueueHandle xQueue,
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597 portTickType xTicksToWait
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600 * This is a macro that calls the xQueueGenericReceive() function.
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602 * Receive an item from a queue. The item is received by copy so a buffer of
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603 * adequate size must be provided. The number of bytes copied into the buffer
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604 * was defined when the queue was created.
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606 * Successfully received items are removed from the queue.
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608 * This function must not be used in an interrupt service routine. See
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609 * xQueueReceiveFromISR for an alternative that can.
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611 * @param pxQueue The handle to the queue from which the item is to be
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614 * @param pvBuffer Pointer to the buffer into which the received item will
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617 * @param xTicksToWait The maximum amount of time the task should block
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618 * waiting for an item to receive should the queue be empty at the time
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619 * of the call. xQueueReceive() will return immediately if xTicksToWait
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620 * is zero and the queue is empty. The time is defined in tick periods so the
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621 * constant portTICK_RATE_MS should be used to convert to real time if this is
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624 * @return pdTRUE if an item was successfully received from the queue,
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625 * otherwise pdFALSE.
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635 xQueueHandle xQueue;
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637 // Task to create a queue and post a value.
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638 void vATask( void *pvParameters )
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640 struct AMessage *pxMessage;
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642 // Create a queue capable of containing 10 pointers to AMessage structures.
\r
643 // These should be passed by pointer as they contain a lot of data.
\r
644 xQueue = xQueueCreate( 10, sizeof( struct AMessage * ) );
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647 // Failed to create the queue.
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652 // Send a pointer to a struct AMessage object. Don't block if the
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653 // queue is already full.
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654 pxMessage = & xMessage;
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655 xQueueSend( xQueue, ( void * ) &pxMessage, ( portTickType ) 0 );
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657 // ... Rest of task code.
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660 // Task to receive from the queue.
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661 void vADifferentTask( void *pvParameters )
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663 struct AMessage *pxRxedMessage;
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667 // Receive a message on the created queue. Block for 10 ticks if a
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668 // message is not immediately available.
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669 if( xQueueReceive( xQueue, &( pxRxedMessage ), ( portTickType ) 10 ) )
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671 // pcRxedMessage now points to the struct AMessage variable posted
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676 // ... Rest of task code.
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679 * \defgroup xQueueReceive xQueueReceive
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680 * \ingroup QueueManagement
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682 #define xQueueReceive( xQueue, pvBuffer, xTicksToWait ) xQueueGenericReceive( ( xQueue ), ( pvBuffer ), ( xTicksToWait ), pdFALSE )
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688 portBASE_TYPE xQueueGenericReceive(
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689 xQueueHandle xQueue,
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691 portTickType xTicksToWait
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692 portBASE_TYPE xJustPeek
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695 * It is preferred that the macro xQueueReceive() be used rather than calling
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696 * this function directly.
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698 * Receive an item from a queue. The item is received by copy so a buffer of
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699 * adequate size must be provided. The number of bytes copied into the buffer
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700 * was defined when the queue was created.
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702 * This function must not be used in an interrupt service routine. See
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703 * xQueueReceiveFromISR for an alternative that can.
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705 * @param pxQueue The handle to the queue from which the item is to be
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708 * @param pvBuffer Pointer to the buffer into which the received item will
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711 * @param xTicksToWait The maximum amount of time the task should block
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712 * waiting for an item to receive should the queue be empty at the time
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713 * of the call. The time is defined in tick periods so the constant
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714 * portTICK_RATE_MS should be used to convert to real time if this is required.
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715 * xQueueGenericReceive() will return immediately if the queue is empty and
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716 * xTicksToWait is 0.
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718 * @param xJustPeek When set to true, the item received from the queue is not
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719 * actually removed from the queue - meaning a subsequent call to
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720 * xQueueReceive() will return the same item. When set to false, the item
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721 * being received from the queue is also removed from the queue.
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723 * @return pdTRUE if an item was successfully received from the queue,
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724 * otherwise pdFALSE.
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734 xQueueHandle xQueue;
\r
736 // Task to create a queue and post a value.
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737 void vATask( void *pvParameters )
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739 struct AMessage *pxMessage;
\r
741 // Create a queue capable of containing 10 pointers to AMessage structures.
\r
742 // These should be passed by pointer as they contain a lot of data.
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743 xQueue = xQueueCreate( 10, sizeof( struct AMessage * ) );
\r
746 // Failed to create the queue.
\r
751 // Send a pointer to a struct AMessage object. Don't block if the
\r
752 // queue is already full.
\r
753 pxMessage = & xMessage;
\r
754 xQueueSend( xQueue, ( void * ) &pxMessage, ( portTickType ) 0 );
\r
756 // ... Rest of task code.
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759 // Task to receive from the queue.
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760 void vADifferentTask( void *pvParameters )
\r
762 struct AMessage *pxRxedMessage;
\r
766 // Receive a message on the created queue. Block for 10 ticks if a
\r
767 // message is not immediately available.
\r
768 if( xQueueGenericReceive( xQueue, &( pxRxedMessage ), ( portTickType ) 10 ) )
\r
770 // pcRxedMessage now points to the struct AMessage variable posted
\r
775 // ... Rest of task code.
\r
778 * \defgroup xQueueReceive xQueueReceive
\r
779 * \ingroup QueueManagement
\r
781 signed portBASE_TYPE xQueueGenericReceive( xQueueHandle xQueue, void * const pvBuffer, portTickType xTicksToWait, portBASE_TYPE xJustPeek );
\r
785 * <pre>unsigned portBASE_TYPE uxQueueMessagesWaiting( const xQueueHandle xQueue );</pre>
\r
787 * Return the number of messages stored in a queue.
\r
789 * @param xQueue A handle to the queue being queried.
\r
791 * @return The number of messages available in the queue.
\r
793 * \page uxQueueMessagesWaiting uxQueueMessagesWaiting
\r
794 * \ingroup QueueManagement
\r
796 unsigned portBASE_TYPE uxQueueMessagesWaiting( const xQueueHandle xQueue );
\r
800 * <pre>void vQueueDelete( xQueueHandle xQueue );</pre>
\r
802 * Delete a queue - freeing all the memory allocated for storing of items
\r
803 * placed on the queue.
\r
805 * @param xQueue A handle to the queue to be deleted.
\r
807 * \page vQueueDelete vQueueDelete
\r
808 * \ingroup QueueManagement
\r
810 void vQueueDelete( xQueueHandle pxQueue );
\r
815 portBASE_TYPE xQueueSendToFrontFromISR(
\r
816 xQueueHandle pxQueue,
\r
817 const void *pvItemToQueue,
\r
818 portBASE_TYPE *pxHigherPriorityTaskWoken
\r
822 * This is a macro that calls xQueueGenericSendFromISR().
\r
824 * Post an item to the front of a queue. It is safe to use this macro from
\r
825 * within an interrupt service routine.
\r
827 * Items are queued by copy not reference so it is preferable to only
\r
828 * queue small items, especially when called from an ISR. In most cases
\r
829 * it would be preferable to store a pointer to the item being queued.
\r
831 * @param xQueue The handle to the queue on which the item is to be posted.
\r
833 * @param pvItemToQueue A pointer to the item that is to be placed on the
\r
834 * queue. The size of the items the queue will hold was defined when the
\r
835 * queue was created, so this many bytes will be copied from pvItemToQueue
\r
836 * into the queue storage area.
\r
838 * @param pxHigherPriorityTaskWoken xQueueSendToFrontFromISR() will set
\r
839 * *pxHigherPriorityTaskWoken to pdTRUE if sending to the queue caused a task
\r
840 * to unblock, and the unblocked task has a priority higher than the currently
\r
841 * running task. If xQueueSendToFromFromISR() sets this value to pdTRUE then
\r
842 * a context switch should be requested before the interrupt is exited.
\r
844 * @return pdTRUE if the data was successfully sent to the queue, otherwise
\r
847 * Example usage for buffered IO (where the ISR can obtain more than one value
\r
850 void vBufferISR( void )
\r
853 portBASE_TYPE xHigherPrioritTaskWoken;
\r
855 // We have not woken a task at the start of the ISR.
\r
856 xHigherPriorityTaskWoken = pdFALSE;
\r
858 // Loop until the buffer is empty.
\r
861 // Obtain a byte from the buffer.
\r
862 cIn = portINPUT_BYTE( RX_REGISTER_ADDRESS );
\r
865 xQueueSendToFrontFromISR( xRxQueue, &cIn, &xHigherPriorityTaskWoken );
\r
867 } while( portINPUT_BYTE( BUFFER_COUNT ) );
\r
869 // Now the buffer is empty we can switch context if necessary.
\r
870 if( xHigherPriorityTaskWoken )
\r
877 * \defgroup xQueueSendFromISR xQueueSendFromISR
\r
878 * \ingroup QueueManagement
\r
880 #define xQueueSendToFrontFromISR( pxQueue, pvItemToQueue, pxHigherPriorityTaskWoken ) xQueueGenericSendFromISR( ( pxQueue ), ( pvItemToQueue ), ( pxHigherPriorityTaskWoken ), queueSEND_TO_FRONT )
\r
886 portBASE_TYPE xQueueSendToBackFromISR(
\r
887 xQueueHandle pxQueue,
\r
888 const void *pvItemToQueue,
\r
889 portBASE_TYPE *pxHigherPriorityTaskWoken
\r
893 * This is a macro that calls xQueueGenericSendFromISR().
\r
895 * Post an item to the back of a queue. It is safe to use this macro from
\r
896 * within an interrupt service routine.
\r
898 * Items are queued by copy not reference so it is preferable to only
\r
899 * queue small items, especially when called from an ISR. In most cases
\r
900 * it would be preferable to store a pointer to the item being queued.
\r
902 * @param xQueue The handle to the queue on which the item is to be posted.
\r
904 * @param pvItemToQueue A pointer to the item that is to be placed on the
\r
905 * queue. The size of the items the queue will hold was defined when the
\r
906 * queue was created, so this many bytes will be copied from pvItemToQueue
\r
907 * into the queue storage area.
\r
909 * @param pxHigherPriorityTaskWoken xQueueSendToBackFromISR() will set
\r
910 * *pxHigherPriorityTaskWoken to pdTRUE if sending to the queue caused a task
\r
911 * to unblock, and the unblocked task has a priority higher than the currently
\r
912 * running task. If xQueueSendToBackFromISR() sets this value to pdTRUE then
\r
913 * a context switch should be requested before the interrupt is exited.
\r
915 * @return pdTRUE if the data was successfully sent to the queue, otherwise
\r
918 * Example usage for buffered IO (where the ISR can obtain more than one value
\r
921 void vBufferISR( void )
\r
924 portBASE_TYPE xHigherPriorityTaskWoken;
\r
926 // We have not woken a task at the start of the ISR.
\r
927 xHigherPriorityTaskWoken = pdFALSE;
\r
929 // Loop until the buffer is empty.
\r
932 // Obtain a byte from the buffer.
\r
933 cIn = portINPUT_BYTE( RX_REGISTER_ADDRESS );
\r
936 xQueueSendToBackFromISR( xRxQueue, &cIn, &xHigherPriorityTaskWoken );
\r
938 } while( portINPUT_BYTE( BUFFER_COUNT ) );
\r
940 // Now the buffer is empty we can switch context if necessary.
\r
941 if( xHigherPriorityTaskWoken )
\r
948 * \defgroup xQueueSendFromISR xQueueSendFromISR
\r
949 * \ingroup QueueManagement
\r
951 #define xQueueSendToBackFromISR( pxQueue, pvItemToQueue, pxHigherPriorityTaskWoken ) xQueueGenericSendFromISR( ( pxQueue ), ( pvItemToQueue ), ( pxHigherPriorityTaskWoken ), queueSEND_TO_BACK )
\r
956 portBASE_TYPE xQueueSendFromISR(
\r
957 xQueueHandle pxQueue,
\r
958 const void *pvItemToQueue,
\r
959 portBASE_TYPE *pxHigherPriorityTaskWoken
\r
963 * This is a macro that calls xQueueGenericSendFromISR(). It is included
\r
964 * for backward compatibility with versions of FreeRTOS.org that did not
\r
965 * include the xQueueSendToBackFromISR() and xQueueSendToFrontFromISR()
\r
968 * Post an item to the back of a queue. It is safe to use this function from
\r
969 * within an interrupt service routine.
\r
971 * Items are queued by copy not reference so it is preferable to only
\r
972 * queue small items, especially when called from an ISR. In most cases
\r
973 * it would be preferable to store a pointer to the item being queued.
\r
975 * @param xQueue The handle to the queue on which the item is to be posted.
\r
977 * @param pvItemToQueue A pointer to the item that is to be placed on the
\r
978 * queue. The size of the items the queue will hold was defined when the
\r
979 * queue was created, so this many bytes will be copied from pvItemToQueue
\r
980 * into the queue storage area.
\r
982 * @param pxHigherPriorityTaskWoken xQueueSendFromISR() will set
\r
983 * *pxHigherPriorityTaskWoken to pdTRUE if sending to the queue caused a task
\r
984 * to unblock, and the unblocked task has a priority higher than the currently
\r
985 * running task. If xQueueSendFromISR() sets this value to pdTRUE then
\r
986 * a context switch should be requested before the interrupt is exited.
\r
988 * @return pdTRUE if the data was successfully sent to the queue, otherwise
\r
991 * Example usage for buffered IO (where the ISR can obtain more than one value
\r
994 void vBufferISR( void )
\r
997 portBASE_TYPE xHigherPriorityTaskWoken;
\r
999 // We have not woken a task at the start of the ISR.
\r
1000 xHigherPriorityTaskWoken = pdFALSE;
\r
1002 // Loop until the buffer is empty.
\r
1005 // Obtain a byte from the buffer.
\r
1006 cIn = portINPUT_BYTE( RX_REGISTER_ADDRESS );
\r
1009 xQueueSendFromISR( xRxQueue, &cIn, &xHigherPriorityTaskWoken );
\r
1011 } while( portINPUT_BYTE( BUFFER_COUNT ) );
\r
1013 // Now the buffer is empty we can switch context if necessary.
\r
1014 if( xHigherPriorityTaskWoken )
\r
1016 // Actual macro used here is port specific.
\r
1017 taskYIELD_FROM_ISR ();
\r
1022 * \defgroup xQueueSendFromISR xQueueSendFromISR
\r
1023 * \ingroup QueueManagement
\r
1025 #define xQueueSendFromISR( pxQueue, pvItemToQueue, pxHigherPriorityTaskWoken ) xQueueGenericSendFromISR( ( pxQueue ), ( pvItemToQueue ), ( pxHigherPriorityTaskWoken ), queueSEND_TO_BACK )
\r
1030 portBASE_TYPE xQueueGenericSendFromISR(
\r
1031 xQueueHandle pxQueue,
\r
1032 const void *pvItemToQueue,
\r
1033 portBASE_TYPE *pxHigherPriorityTaskWoken,
\r
1034 portBASE_TYPE xCopyPosition
\r
1038 * It is preferred that the macros xQueueSendFromISR(),
\r
1039 * xQueueSendToFrontFromISR() and xQueueSendToBackFromISR() be used in place
\r
1040 * of calling this function directly.
\r
1042 * Post an item on a queue. It is safe to use this function from within an
\r
1043 * interrupt service routine.
\r
1045 * Items are queued by copy not reference so it is preferable to only
\r
1046 * queue small items, especially when called from an ISR. In most cases
\r
1047 * it would be preferable to store a pointer to the item being queued.
\r
1049 * @param xQueue The handle to the queue on which the item is to be posted.
\r
1051 * @param pvItemToQueue A pointer to the item that is to be placed on the
\r
1052 * queue. The size of the items the queue will hold was defined when the
\r
1053 * queue was created, so this many bytes will be copied from pvItemToQueue
\r
1054 * into the queue storage area.
\r
1056 * @param pxHigherPriorityTaskWoken xQueueGenericSendFromISR() will set
\r
1057 * *pxHigherPriorityTaskWoken to pdTRUE if sending to the queue caused a task
\r
1058 * to unblock, and the unblocked task has a priority higher than the currently
\r
1059 * running task. If xQueueGenericSendFromISR() sets this value to pdTRUE then
\r
1060 * a context switch should be requested before the interrupt is exited.
\r
1062 * @param xCopyPosition Can take the value queueSEND_TO_BACK to place the
\r
1063 * item at the back of the queue, or queueSEND_TO_FRONT to place the item
\r
1064 * at the front of the queue (for high priority messages).
\r
1066 * @return pdTRUE if the data was successfully sent to the queue, otherwise
\r
1069 * Example usage for buffered IO (where the ISR can obtain more than one value
\r
1072 void vBufferISR( void )
\r
1075 portBASE_TYPE xHigherPriorityTaskWokenByPost;
\r
1077 // We have not woken a task at the start of the ISR.
\r
1078 xHigherPriorityTaskWokenByPost = pdFALSE;
\r
1080 // Loop until the buffer is empty.
\r
1083 // Obtain a byte from the buffer.
\r
1084 cIn = portINPUT_BYTE( RX_REGISTER_ADDRESS );
\r
1086 // Post each byte.
\r
1087 xQueueGenericSendFromISR( xRxQueue, &cIn, &xHigherPriorityTaskWokenByPost, queueSEND_TO_BACK );
\r
1089 } while( portINPUT_BYTE( BUFFER_COUNT ) );
\r
1091 // Now the buffer is empty we can switch context if necessary. Note that the
\r
1092 // name of the yield function required is port specific.
\r
1093 if( xHigherPriorityTaskWokenByPost )
\r
1095 taskYIELD_YIELD_FROM_ISR();
\r
1100 * \defgroup xQueueSendFromISR xQueueSendFromISR
\r
1101 * \ingroup QueueManagement
\r
1103 signed portBASE_TYPE xQueueGenericSendFromISR( xQueueHandle pxQueue, const void * const pvItemToQueue, signed portBASE_TYPE *pxHigherPriorityTaskWoken, portBASE_TYPE xCopyPosition );
\r
1108 portBASE_TYPE xQueueReceiveFromISR(
\r
1109 xQueueHandle pxQueue,
\r
1111 portBASE_TYPE *pxTaskWoken
\r
1115 * Receive an item from a queue. It is safe to use this function from within an
\r
1116 * interrupt service routine.
\r
1118 * @param pxQueue The handle to the queue from which the item is to be
\r
1121 * @param pvBuffer Pointer to the buffer into which the received item will
\r
1124 * @param pxTaskWoken A task may be blocked waiting for space to become
\r
1125 * available on the queue. If xQueueReceiveFromISR causes such a task to
\r
1126 * unblock *pxTaskWoken will get set to pdTRUE, otherwise *pxTaskWoken will
\r
1127 * remain unchanged.
\r
1129 * @return pdTRUE if an item was successfully received from the queue,
\r
1130 * otherwise pdFALSE.
\r
1135 xQueueHandle xQueue;
\r
1137 // Function to create a queue and post some values.
\r
1138 void vAFunction( void *pvParameters )
\r
1140 char cValueToPost;
\r
1141 const portTickType xBlockTime = ( portTickType )0xff;
\r
1143 // Create a queue capable of containing 10 characters.
\r
1144 xQueue = xQueueCreate( 10, sizeof( char ) );
\r
1147 // Failed to create the queue.
\r
1152 // Post some characters that will be used within an ISR. If the queue
\r
1153 // is full then this task will block for xBlockTime ticks.
\r
1154 cValueToPost = 'a';
\r
1155 xQueueSend( xQueue, ( void * ) &cValueToPost, xBlockTime );
\r
1156 cValueToPost = 'b';
\r
1157 xQueueSend( xQueue, ( void * ) &cValueToPost, xBlockTime );
\r
1159 // ... keep posting characters ... this task may block when the queue
\r
1162 cValueToPost = 'c';
\r
1163 xQueueSend( xQueue, ( void * ) &cValueToPost, xBlockTime );
\r
1166 // ISR that outputs all the characters received on the queue.
\r
1167 void vISR_Routine( void )
\r
1169 portBASE_TYPE xTaskWokenByReceive = pdFALSE;
\r
1172 while( xQueueReceiveFromISR( xQueue, ( void * ) &cRxedChar, &xTaskWokenByReceive) )
\r
1174 // A character was received. Output the character now.
\r
1175 vOutputCharacter( cRxedChar );
\r
1177 // If removing the character from the queue woke the task that was
\r
1178 // posting onto the queue cTaskWokenByReceive will have been set to
\r
1179 // pdTRUE. No matter how many times this loop iterates only one
\r
1180 // task will be woken.
\r
1183 if( cTaskWokenByPost != ( char ) pdFALSE;
\r
1189 * \defgroup xQueueReceiveFromISR xQueueReceiveFromISR
\r
1190 * \ingroup QueueManagement
\r
1192 signed portBASE_TYPE xQueueReceiveFromISR( xQueueHandle pxQueue, void * const pvBuffer, signed portBASE_TYPE *pxHigherPriorityTaskWoken );
\r
1195 * Utilities to query queues that are safe to use from an ISR. These utilities
\r
1196 * should be used only from witin an ISR, or within a critical section.
\r
1198 signed portBASE_TYPE xQueueIsQueueEmptyFromISR( const xQueueHandle pxQueue );
\r
1199 signed portBASE_TYPE xQueueIsQueueFullFromISR( const xQueueHandle pxQueue );
\r
1200 unsigned portBASE_TYPE uxQueueMessagesWaitingFromISR( const xQueueHandle pxQueue );
\r
1204 * xQueueAltGenericSend() is an alternative version of xQueueGenericSend().
\r
1205 * Likewise xQueueAltGenericReceive() is an alternative version of
\r
1206 * xQueueGenericReceive().
\r
1208 * The source code that implements the alternative (Alt) API is much
\r
1209 * simpler because it executes everything from within a critical section.
\r
1210 * This is the approach taken by many other RTOSes, but FreeRTOS.org has the
\r
1211 * preferred fully featured API too. The fully featured API has more
\r
1212 * complex code that takes longer to execute, but makes much less use of
\r
1213 * critical sections. Therefore the alternative API sacrifices interrupt
\r
1214 * responsiveness to gain execution speed, whereas the fully featured API
\r
1215 * sacrifices execution speed to ensure better interrupt responsiveness.
\r
1217 signed portBASE_TYPE xQueueAltGenericSend( xQueueHandle pxQueue, const void * const pvItemToQueue, portTickType xTicksToWait, portBASE_TYPE xCopyPosition );
\r
1218 signed portBASE_TYPE xQueueAltGenericReceive( xQueueHandle pxQueue, void * const pvBuffer, portTickType xTicksToWait, portBASE_TYPE xJustPeeking );
\r
1219 #define xQueueAltSendToFront( xQueue, pvItemToQueue, xTicksToWait ) xQueueAltGenericSend( ( xQueue ), ( pvItemToQueue ), ( xTicksToWait ), queueSEND_TO_FRONT )
\r
1220 #define xQueueAltSendToBack( xQueue, pvItemToQueue, xTicksToWait ) xQueueAltGenericSend( ( xQueue ), ( pvItemToQueue ), ( xTicksToWait ), queueSEND_TO_BACK )
\r
1221 #define xQueueAltReceive( xQueue, pvBuffer, xTicksToWait ) xQueueAltGenericReceive( ( xQueue ), ( pvBuffer ), ( xTicksToWait ), pdFALSE )
\r
1222 #define xQueueAltPeek( xQueue, pvBuffer, xTicksToWait ) xQueueAltGenericReceive( ( xQueue ), ( pvBuffer ), ( xTicksToWait ), pdTRUE )
\r
1225 * The functions defined above are for passing data to and from tasks. The
\r
1226 * functions below are the equivalents for passing data to and from
\r
1229 * These functions are called from the co-routine macro implementation and
\r
1230 * should not be called directly from application code. Instead use the macro
\r
1231 * wrappers defined within croutine.h.
\r
1233 signed portBASE_TYPE xQueueCRSendFromISR( xQueueHandle pxQueue, const void *pvItemToQueue, signed portBASE_TYPE xCoRoutinePreviouslyWoken );
\r
1234 signed portBASE_TYPE xQueueCRReceiveFromISR( xQueueHandle pxQueue, void *pvBuffer, signed portBASE_TYPE *pxTaskWoken );
\r
1235 signed portBASE_TYPE xQueueCRSend( xQueueHandle pxQueue, const void *pvItemToQueue, portTickType xTicksToWait );
\r
1236 signed portBASE_TYPE xQueueCRReceive( xQueueHandle pxQueue, void *pvBuffer, portTickType xTicksToWait );
\r
1239 * For internal use only. Use xSemaphoreCreateMutex(),
\r
1240 * xSemaphoreCreateCounting() or xSemaphoreGetMutexHolder() instead of calling
\r
1241 * these functions directly.
\r
1243 xQueueHandle xQueueCreateMutex( unsigned char ucQueueType );
\r
1244 xQueueHandle xQueueCreateCountingSemaphore( unsigned portBASE_TYPE uxCountValue, unsigned portBASE_TYPE uxInitialCount );
\r
1245 void* xQueueGetMutexHolder( xQueueHandle xSemaphore );
\r
1248 * For internal use only. Use xSemaphoreTakeMutexRecursive() or
\r
1249 * xSemaphoreGiveMutexRecursive() instead of calling these functions directly.
\r
1251 portBASE_TYPE xQueueTakeMutexRecursive( xQueueHandle pxMutex, portTickType xBlockTime );
\r
1252 portBASE_TYPE xQueueGiveMutexRecursive( xQueueHandle pxMutex );
\r
1255 * Reset a queue back to its original empty state. pdPASS is returned if the
\r
1256 * queue is successfully reset. pdFAIL is returned if the queue could not be
\r
1257 * reset because there are tasks blocked on the queue waiting to either
\r
1258 * receive from the queue or send to the queue.
\r
1260 #define xQueueReset( pxQueue ) xQueueGenericReset( pxQueue, pdFALSE )
\r
1263 * The registry is provided as a means for kernel aware debuggers to
\r
1264 * locate queues, semaphores and mutexes. Call vQueueAddToRegistry() add
\r
1265 * a queue, semaphore or mutex handle to the registry if you want the handle
\r
1266 * to be available to a kernel aware debugger. If you are not using a kernel
\r
1267 * aware debugger then this function can be ignored.
\r
1269 * configQUEUE_REGISTRY_SIZE defines the maximum number of handles the
\r
1270 * registry can hold. configQUEUE_REGISTRY_SIZE must be greater than 0
\r
1271 * within FreeRTOSConfig.h for the registry to be available. Its value
\r
1272 * does not effect the number of queues, semaphores and mutexes that can be
\r
1273 * created - just the number that the registry can hold.
\r
1275 * @param xQueue The handle of the queue being added to the registry. This
\r
1276 * is the handle returned by a call to xQueueCreate(). Semaphore and mutex
\r
1277 * handles can also be passed in here.
\r
1279 * @param pcName The name to be associated with the handle. This is the
\r
1280 * name that the kernel aware debugger will display.
\r
1282 #if configQUEUE_REGISTRY_SIZE > 0U
\r
1283 void vQueueAddToRegistry( xQueueHandle xQueue, signed char *pcName );
\r
1287 * Generic version of the queue creation function, which is in turn called by
\r
1288 * any queue, semaphore or mutex creation function or macro.
\r
1290 xQueueHandle xQueueGenericCreate( unsigned portBASE_TYPE uxQueueLength, unsigned portBASE_TYPE uxItemSize, unsigned char ucQueueType );
\r
1292 /* Not public API functions. */
\r
1293 void vQueueWaitForMessageRestricted( xQueueHandle pxQueue, portTickType xTicksToWait );
\r
1294 portBASE_TYPE xQueueGenericReset( xQueueHandle pxQueue, portBASE_TYPE xNewQueue );
\r
1297 #ifdef __cplusplus
\r
1301 #endif /* QUEUE_H */
\r
projects / freertos / blob